Reaktion #87118

Reaktionsgleichung

N,O-dimethylhydroxylamine HCl

(S)-2-((tert-butoxycarbonyl)amino)-3-cyclopentylpropanoic acid

ethyl chloroformate

NMM

→

(S)-tert-butyl (3-cyclopentyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate

Ausbeute 93.3%

Lösungsmittel

DCM

THF DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   TemperaturThe mixture was cooled to 0° C.
3. 3
   Temperaturto warm to ambient temperature
4. 4
   workup.STIRRINGstirred overnight
5. 5
   SonstigeThe reaction was then quenched with water (500 mL)
6. 6
   Sonstigethe two phases were separated
7. 7
   WaschenThe organic phase was washed with water (500 mL)
8. 8
   Trocknendried over anhydrous sodium sulfate
9. 9
   Einengenconcentrated

Vorschrift

To a flask charged with compound (S)-2-((tert-butoxycarbonyl)amino)-3-cyclopentylpropanoic acid (55.0 g, 214 mmol) was added THF/DCM (800 mL, 1:1). The solution was cooled to 0° C. and ethyl chloroformate (24.5 mL, 257 mmol) and NMM (28.4 mL, 257 mmol) was added dropwise sequentially. After addition, the mixture was stirred at 0° C. under nitrogen for 1 h. To the other flask charged with N,O-dimethylhydroxylamine HCl (25.0 g, 257 mmol) was added DCM (400 mL). The mixture was cooled to 0° C. and TEA (38.7 mL, 278 mmol) was added. The resulting mixture was transferred into the former reaction flask. The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The reaction was then quenched with water (500 mL) and the two phases were separated. The organic phase was washed with water (500 mL), dried over anhydrous sodium sulfate, and concentrated to afford (S)-tert-butyl (3-cyclopentyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate as colorless oil (60 g, 93% yield), which was used in the next step without further purification.

Quelle